Wireless transmission system



Jan. 21, 1936. J. HJRUBENSTEIN g- 19,834

WIRELESS TRANSMISSION SYSTEM Original Filed Feb. 18, 1952 INVENTOR.

ATTO RN EY.

Reissued Jan. 21, 1936 R 19,834

WIRELESS TRANSMISSION SYSTEM Jacob H. Rubenstein, Syracuse, N. Y.

Original No. 1,906,769, dated May 2, 1933, Serial No. 593,819, February 18, 1932. Application for reissue April 26, 1935, Serial No. 18,423

7 Claims. (Cl. 1792) This invention relates to 'a wireless system tions for household or offlce conveniences, and whereby audio signals may be transmitted and wherein the entire series of local receiving sets received through an electric lighting circuit may be under the control of a master radio ground and an auxiliary ground, and has for its (not shown), which may be equipped with anobject to provide such a system wherein music, tenna, dials, and audio amplifier, and may be set 5 speech, or other signals may be received, amplionce or oftener each day to transmit to the local fled and simultaneously distributed to head sets programs or signals of different wave lengths, phones or loud speakers, which may be arranged the persons seeking the entertainment having no in multiple across the two grounds and may be duties to perform except to simply turn on and 10 located in various rooms of hotels, hospitals, turn off their individual receiving sets. This 10 dwellings, orthelike. Afurther object is to conmaster radio may be located in any part of a neet a very low impedance secondary coil across building within convenient reach of the lighting the two grounds and couple thereto a primary circuit and auxiliary grounds. or output of an audio amplifier, whereby audio Referring to the drawing, 2-3 represent the frequency currents may be induced in the said conductors of the lighting system, the wire 3 be- 15 ground lines. A further object is to connect being grounded, as at 3', and I represents a water or tween the said ground lines, at any suitable point, gas pipe which may serve as the auxiliary ground.

a coil, or a plurality of coils (head phones or loud 5 represents a relatively low impedance secondary speakers), whose impedance in circuit with the coil, which is connected across the grounds 3 and secondary coil is low like that of the secondary 4, to which is coupled a primary coil, as 6, the 20 coil and preferably substantially matches the imlatter being virtually the output of an audio ampedance of said secondary coil, whereby the plifier (not shown). By this peculiar arrangeaudio energy may be reconvcrted into sound ment, it has been proven that audio energy or ourwaves or audible frequency at a maximum efllrents may be induced in the grounds 3-4 of sumciency. And a further object is to provide an excient potential to operate a number of independ- 25 tremely simple, economic, and automatic transent audio receiving and transmitting sets. In mission system for the reception and distribution this connection, it may be explained that actual of entertainment programs and other signals, that measurements of resistance from the ground wire requires no special wiring of any buildings, in 9 to the auxiliary ground 4 taken, for example,

order to receive and transmit audio and other on the dotted lines 3:: of Figs. 1 and 2 shows that 30 signals as long as a fighting circuit ground and the said resistance varies with difierent AC outan auxiliary ground may beconveniently utilized lets, the range being anywhere from /2 to 10 for the pin-pose. ohms. It has further been found that the very I attain these objects by the means set forth low impedance secondary coil 5 may be conin the detailed description which follows, and as nected across the lines 3-4 without much loss of 35 illustrated by the accompanying drawing, in energy in said lines due to their mutual grounding whichand the impedance of the secondary 5 being less Figure 1 shows diagrammatically an electric than the ohmic resistance from line 3 to line 4. lighting cicuit having one wire grounded and an It having been demonstrated by the foregoing arauxiliary ground, also showing output of an audio rangement and tests that audio currents may be 40 amplifier, and audio receiving sets equipped with induced in lines 3 and 4, the next step contemloud speakers; and plates connecting at any suitable point, as in the Figure 2 shows the substitution of a number portions 3a4a. of lines 3--4,one or more primary of head phones for the loud speakers of Fig. l, coils, as |--Ic, in order to reconvert the audio also showing condensers in each of the head energy into sound waves or audible frequency 45 phone circuits. that will effect the perfect rendition of music,

The invention contemplates the establishment speech of other pro The 60115 are P of a wireless transmission system, wherein an inerably c p to Secondary c s ose imdefinite number of the individual receiving sets, pedance approximately matches the loud speaksuch as head phones and loud speaker units may ers, as Ia. Any suitable number of the coils or 50 be connected in parallel across two ground lines, receiving devices 1'1c may be connected in parone of said lines preferably comprising the allel across the lines 3-4 and constitute a series of grounded side of any ordinary electric lighting individual sets which may be located in the varisystem, the other line comprising a water, gas, or ous rooms of apartment houses, omce buildings steam pipe, forming parts oi the usual installaand hotels and simultaneously render identical 55,

programs under the control of the master radio, as explained. By this construction and arrangement, programs or signals of varying wave lengths may be selected by the master radio and rendered simultaneously throughout the said building, at the will of the owners of occupants of the rooms, without liability of any interference and without battery, or machine generated current carrying wires, except as shown in the diagrams 1 and 2.

Condensers, as 8, shown in Fig. 2, may be coupled with head phone circuits or coils 1c, in order to eliminate any lighting circuit frequency humming that may be educed by the ground 3. This elimination of the humming is facilitated by the higher frequency in the condensers 8, as compared with the relatively low frequency of the lighting circuit 2-3, which enables the condensers to prevent the passing of said low frequency humming. On the other hand, in the case of the loud speaker circuits (see Fig. 1), due to the low impedance of the primary coils I and the higher impedance of the coils 1', the humming of the lighting circuit 2-3 is automatically eliminated without the aid of the condensers 8.

In case some of the rooms of a building are equipped with audio frequency producers of the loud speaker type, while other rooms have only the ordinary head phones, provision is made for diversifying the installations, as may be understood by comparing Fig. 1 with Fig. 2 of the drawing, wherein are respectively shown loud speaker circuits 1-1'; or else simple head-set circuits, as To. In either case, the installation of the diversifled and interchangeable equipment simply consists of connecting the said circuits in parallel across the grounds 3 and 4, which requires only a few minutes time, and the utilization of transmitting facilities generally common to such rooms that have not heretofore been collectively employed in connection with audio or radio-frequency transmission as herein shown.

From the foregoing, it will be apparent that the important and novel feature of the present system of transmission resides in the fact that practically all of the ethereal productions may be received and transmitted without the necessity of equipping any of the modern buildings with special wires to perform the services of the grounds I and l, which are now shown to be available for audio frequency transmission without any installation labor or expense.

The present invention comprehends the use of any suitable master radio, and standard audio amplifiers, condensers, dials and the like, and since these devices are all well-known, none of them are shown or described in detail herein.

Obviously, any well-known non-inductive resistance may be shunted across the earphones for a hum filter instead of the series condensers, and other modifications and changes may also be made within the scope defined by the appended claims.

The present invention is extremely simple, and may be produced, installed, and operated at exceedingly low cost. By utilizing the grounded side 3 of the electric lighting circuit and an auxiliary ground line, as 4, which may comprise any common water, gas or steam pipe, both of the said lines being common to practically all large buildings, as well as most of the urban residences or dwellings, a satisfactory local transmission medium may be obtained with very little labor or expense, and the same ground lines may be resorted to wherever they may be found in a building, for the purpose of installing single series comprising a large number of the individual receiving and transmitting sets 'l-l and 1c. without consuming any of the electric power of the lighting circuit 2-3, and without in any way weakening or interfering with the normal services of the said circuit.

Having thus described my invention, what I claim, is- 1 1. A transmission system having in combination with the grounded conductor of an electric lighting system and an auxiliary ground, an audio amplifier including an output primary coil, a low impedance secondary coil connected across said grounds and coupled with said output primary coil, a plurality of low impedance coils connected across said grounds in parallel, a plurality of loud speakers, and secondary coils coupled with the plurality of low impedance coils to transmit audible frequency currents from said grounds to the loud speakers.

2. A signal distributing system comprising an audio amplifier including an output primary coil, a. pair of ground lines, a low impedance coil connected across said lines and coupled to said output coil whereby audio frequency currents may be induced in said ground lines, a plurality of coils whose total impedance approximates the impedance of said low impedance coil connected in parallel across said grounds whereby the audio energy in said grounds may be reconverted into audible frequency, a plurality of loud speakers, and a plurality of secondary coils coupled to the last named low impedance coils to transmit the audible frequency to said loud speakers.

3. The combination with a master radio including an audio amplifier and an output primary coil, of a pair of grounds one being a conductor of an electric lighting circuit, a low impedance coil connected across said grounds and coupled with said output primary coil, a plurality of low impedance primary coils connected in parallel across said grounds, a plurality of audible frequency receiving sets, including secondary coils whose impedance matches said sets coupled with the low impedance primary coils to transmit the audible frequency signals to the users of said sets.

4. A signal distributing system having in combination with a master radio and an audio amplifier including an output primary coil, a pair of grounded lines one line forming part of an electric lighting circuit, a low impedance secondary coil connected across said grounded lines and coupled with said output coil adapted to induce audio frequency currents in said grounded lines, a plurality of low impedance coils connected in parallel across said grounded lines adapted to reconvert the audio energy in said lines into sound waves, a plurality of loud speakers, and secondary coils coupled to the low impedance coils adapted to transmit the sound waves to the loud speakers.

5. A wireless transmission system having in combination with the grounded conductor of an electric lighting circuit and an auxiliary ground, and a master radio to control said system, an audio amplifier including an output primary coil, a low impedance secondary coil connected across said grounds and coupled with said output coil adapted to induce audio frequency currents in said grounds, a plurality of low impedance coils connected in parallel across said grounds and spaced progressively from said secondary coil adapted to reconvert said audio frequency currents in said grounds into sound waves, a plurality of loud speakers, and secondary coils coupled with the low impedance coils adapted to transmit the sound waves to the loud speakers.

6. A signal transmission system having in combination with the grounded conductor of an electric lighting system and an auxiliary ground, an audio amplifier including an output primary coil, a low impedance secondary coil connected across said grounds and coupledwith said output primary coil, a plurality of low impedance coils connected across said grounds in parallel, and a plurality of receiving sets including secondary coils of low impedance receiving devices connected 10 across said grounds adapted to convert the audio frequency currents in said ground lines into sound waves.

JACOB H. RUBENSTEIN. 

